Network slice selection in cellular system

ABSTRACT

This document discloses a solution for selecting a network slice for an application. According to an aspect, a method comprises as performed by a terminal device: triggering, by the terminal device, network slice selection in the terminal device for an application executed in the terminal device; transmitting, by the terminal device in response to said triggering, a network slice query request message to a network node of a network infrastructure; receiving, by the terminal device from the network node as a response to the network slice query request message, a network slice query response message indicating at least one network slice available to the terminal device and comprising at least one quality-of-service parameter of the at least one network slice; and selecting, by the terminal device, a network slice of the at least one network slice for the application on the basis of the at least one quality-of-service parameter.

FIELD

Various embodiments described herein relate to the field of wirelesscommunications and, particularly, to selecting a network slice for aterminal device in a cellular communication system.

BACKGROUND

Network slicing is a concept where network resources of an end-to-endconnection between a user device and another end point in a public landmobile network (PLMN) are sliced. Similar network slicing may beemployed in private networks. A network slice may be understood as alogical end-to-end network that can be dynamically created and/ormodified. The network(s) between the end devices may all be sliced fromone end device to the other end device, the slices thus forming logicalpipelines within the network(s) using the same physical networkinfrastructure. User equipment (UE) may access a slice over a radiointerface. Each pipeline/slice may serve a particular service type suchas enhanced mobile broadband (eMBB), ultra-reliable low latencycommunications (URLLC), or massive Internet of Things (MIoT), forexample. MIoT is in some literature called Massive Machine TypeCommunications (MMTC). Other slices and corresponding service types maybe envisaged. Each service type may have distinct characteristicsregarding a quality of service (QoS). For example, eMBB may supportmechanisms for high bandwidth with moderate delays, URLLC may supportmechanisms for low latencies and high reliability of data transfer, andMIoT may support low power consumption at the UE.

BRIEF DESCRIPTION

Some aspects of the invention are defined by the independent claims.

Some embodiments of the invention are defined in the dependent claims.

The embodiments and features, if any, described in this specificationthat do not fall under the scope of the independent claims are to beinterpreted as examples useful for understanding various embodiments ofthe invention. Some aspects of the disclosure are defined by theindependent claims.

According to an aspect, there is provided an apparatus for a terminaldevice, comprising means for performing: triggering network sliceselection in the terminal device for an application executed in theterminal device; in response to said triggering, causing transmission ofa network slice query request message to a network node of a networkinfrastructure; receiving, from the network node as a response to thenetwork slice query request message, a network slice query responsemessage indicating at least one network slice available to the terminaldevice and comprising at least one quality-of-service parameter of theat least one network slice; and selecting a network slice of the atleast one network slice for the application on the basis of the at leastone quality-of-service parameter.

In an embodiment, the means are configured to perform said selecting byat least transmitting to the network node a request to configure arouting policy for data of the application in the selected networkslice.

In an embodiment, the request to configure the routing policy comprisesat least one information element indicating an identity of theapplication.

In an embodiment, the network slice query request message comprises atleast one information element specifying at least one criterion, andwherein the at least one network slice indicated by the network slicequery response message meets the at least one criterion.

In an embodiment, the means are configured to perform said triggering asresponsive to the application requesting for data transfer withdetermined quality-of-service constraints.

According to an aspect, there is provided an apparatus for a networknode of a network infrastructure, comprising means for performing:receiving a network slice query request message from a terminal devicerequesting for information on available network slices; determining atleast one network slice available to the terminal device; transmitting,to the terminal device as a response to the network slice query requestmessage, a network slice query response message that indicates the atleast one network slice available to the terminal device and thatcomprises at least one quality-of-service parameter of the at least onenetwork slice; receiving, from the terminal device, a message indicatinga selection of a network slice for an application executed in theterminal device; and configuring a routing policy for data of theapplication in the selected network slice in the network infrastructure.

In an embodiment, the message indicating the selection of the networkslice comprises at least one information element indicating an identityof the application.

In an embodiment, the network slice query request message comprises atleast one information element specifying at least one criterion, andwherein the at least one memory and computer program code configured to,with the at least one processor, cause the apparatus to include in thenetwork slice query response message network slices that meet the atleast one criterion and exclude from the network slice query responsemessage at least one network slice not meeting the at least onecriterion.

In an embodiment, the above-described means comprise at least oneprocessor and at least one memory including computer program code,wherein the at least one memory and computer program code configured to,with the at least one processor, cause the performance of the apparatus.

According to an aspect, there is provided a method for a terminaldevice, comprising: triggering, by the terminal device, network sliceselection in the terminal device for an application executed in theterminal device; transmitting, by the terminal device in response tosaid triggering, a network slice query request message to a network nodeof a network infrastructure; receiving, by the terminal device from thenetwork node as a response to the network slice query request message, anetwork slice query response message indicating at least one networkslice available to the terminal device and comprising at least onequality-of-service parameter of the at least one network slice; andselecting, by the terminal device, a network slice of the at least onenetwork slice for the application on the basis of the at least onequality-of-service parameter.

In an embodiment, said selecting comprises transmitting to the networknode a request to configure a routing policy for data of the applicationin the selected network slice.

In an embodiment, the request to configure the routing policy comprisesat least one information element indicating an identity of theapplication.

According to an aspect, there is provided a method for a network node ofa network infrastructure, comprising: receiving, by the network node, anetwork slice query request message from a terminal device requestingfor information on available network slices; determining, by the networknode, at least one network slice available to the terminal device;transmitting, by the network node to the terminal device as a responseto the network slice query request message, a network slice queryresponse message that indicates the at least one network slice availableto the terminal device and that comprises at least onequality-of-service parameter of the at least one network slice;receiving, by the network node from the terminal device, a messageindicating selection of a network slice for an application executed inthe terminal device; and configuring, by the network node, a routingpolicy for data of the application in the selected network slice in thenetwork infrastructure.

In an embodiment, the message indicating the selection of the networkslice comprises at least one information element indicating an identityof the application.

In an embodiment, the network slice query request message comprises atleast one information element specifying at least one criterion, themethod further comprising including, by the network node in the networkslice query response message, network slices that meet the at least onecriterion and excluding, by the network node, from the network slicequery response message at least one network slice not meeting the atleast one criterion.

According to an aspect, there is provided a computer program productembodied on a computer-readable medium and comprising a computer programcode readable by a computer, wherein the computer program codeconfigures the computer to carry out a computer process comprising allthe steps of any one of the above-described methods.

According to an aspect, there is provided a system comprising any one ofthe above-described apparatuses for the terminal device and any one ofthe above-described apparatuses for the network node.

LIST OF DRAWINGS

Embodiments are described below, by way of example only, with referenceto the accompanying drawings, in which

FIG. 1 illustrates a wireless communication scenario to which someembodiments of the invention may be applied;

FIGS. 2A and 2B illustrate utilization of network slices in a networkinfrastructure;

FIGS. 3 and 4 illustrate processes for performing network sliceselection for an application executed in a terminal device according tosome embodiments;

FIG. 5 illustrates a signalling diagram according to an embodimentcombining the processes of FIGS. 3 and 4;

FIG. 6 illustrates an embodiment of a network slice selection process inthe terminal device; and

FIGS. 7 and 8 illustrate block diagrams of structures of apparatusesaccording to some embodiments of the invention.

DESCRIPTION OF EMBODIMENTS

The following embodiments are examples. Although the specification mayrefer to “an”, “one”, or “some” embodiment(s) in several locations, thisdoes not necessarily mean that each such reference is to the sameembodiment(s), or that the feature only applies to a single embodiment.Single features of different embodiments may also be combined to provideother embodiments. Furthermore, words “comprising” and “including”should be understood as not limiting the described embodiments toconsist of only those features that have been mentioned and suchembodiments may contain also features/structures that have not beenspecifically mentioned.

In the following, different exemplifying embodiments will be describedusing, as an example of an access architecture to which the embodimentsmay be applied, a radio access architecture based on long term evolutionadvanced (LTE Advanced, LTE-A) or new radio (NR, 5G), withoutrestricting the embodiments to such an architecture, however. Theembodiments may also be applied to other kinds of communicationsnetworks having suitable means by adjusting parameters and proceduresappropriately. Some examples of other options for suitable systems arethe universal mobile telecommunications system (UMTS) radio accessnetwork (UTRAN or E-UTRAN), long term evolution (LTE, the same asE-UTRA), wireline or wireless local area network (e.g. WLAN or WiFi orBBF/Cable access), worldwide interoperability for microwave access(WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®,wideband code division multiple access (WCDMA), systems usingultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks(MANETs) and Internet Protocol multimedia subsystems (IMS) or anycombination thereof.

FIG. 1 depicts examples of simplified system architectures only showingsome elements and functional entities, all being logical units, whoseimplementation may differ from what is shown. The connections shown inFIG. 1 are logical connections; the actual physical connections may bedifferent. It is apparent to a person skilled in the art that the systemtypically comprises also other functions and structures than those shownin FIG. 1.

The embodiments are not, however, restricted to the system given as anexample but a person skilled in the art may apply the solution to othercommunication systems provided with necessary properties.

The example of FIG. 1 shows a part of an exemplifying radio accessnetwork but the solution can apply to other types of access networkssuch as wireline or trusted/untrusted access to the cellular corenetwork.

FIG. 1 shows devices 100 and 102. The devices 100 and 102 may, forexample, be user devices. The devices 100 and 102 are configured to bein a wireless connection on one or more communication channels with anode 104. The node 104 is further connected to a core network 110. Inone example, the node 104 may be an access node such as (e/g)NodeBproviding or serving devices in a cell. In one example, the node 104 maybe a non-3GPP access node. The physical link from a device to a(e/g)NodeB is called uplink or reverse link and the physical link fromthe (e/g)NodeB to the device is called downlink or forward link. Itshould be appreciated that (e/g)NodeBs or their functionalities may beimplemented by using any node, host, server or access point etc. entitysuitable for such a usage.

A communications system typically comprises more than one (e/g)NodeB inwhich case the (e/g)NodeBs may also be configured to communicate withone another over links, wired or wireless, designed for the purpose.These links may be used for signalling purposes. The (e/g)NodeB is acomputing device configured to control the radio resources ofcommunication system it is coupled to. The NodeB may also be referred toas a base station, an access point or any other type of interfacingdevice including a relay station capable of operating in a wirelessenvironment. The (e/g)NodeB includes or is coupled to transceivers. Fromthe transceivers of the (e/g)NodeB, a connection is provided to anantenna unit that establishes bi-directional radio links to devices. Theantenna unit may comprise a plurality of antennas or antenna elements.The (e/g)NodeB is further connected to the core network 110 (CN or nextgeneration core 5GC). Depending on the system, the counterpart on the CNside can be an AMF (Access and Mobility management Function), Sessionmanagement Function (SMF) and Policy Control Function (PCF), forproviding connectivity of devices (UEs) to external packet datanetworks, etc.

The device (also called user device, UE, user equipment, user terminal,terminal device, etc.) illustrates one type of an apparatus to whichresources on the air interface are allocated and assigned, and thus anyfeature described herein with a device may be implemented with acorresponding apparatus, such as a relay node. An example of such arelay node is a layer 3 relay (self-backhauling relay) towards the basestation.

The device typically refers to a device (e.g. a portable or non-portablecomputing device) that includes wireless mobile communication devicesoperating with or without a subscriber identification module (SIM),including, but not limited to, the following types of devices: a mobilestation (mobile phone), smartphone, personal digital assistant (PDA),handset, device using a wireless modem (alarm or measurement device,etc.), laptop and/or touch screen computer, tablet, game console,notebook, and multimedia device. It should be appreciated that a devicemay also be a nearly exclusive uplink only device, of which an exampleis a camera or video camera loading images or video clips to a network.A device may also be a device having capability to operate in Internetof Things (IoT) network which is a scenario in which objects areprovided with the ability to transfer data over a network withoutrequiring human-to-human or human-to-computer interaction, e.g. to beused in smart power grids and connected vehicles. The device may alsoutilise cloud. In some applications, a device may comprise a userportable device with radio parts (such as a watch, earphones oreyeglasses) and the computation is carried out in the cloud. The device(or in some embodiments a layer 3 relay node) is configured to performone or more of user equipment functionalities. The device may also becalled a subscriber unit, mobile station, remote terminal, accessterminal, user terminal or user equipment (UE) just to mention but a fewnames or apparatuses.

Various techniques described herein may also be applied to acyber-physical system (CPS) (a system of collaborating computationalelements controlling physical entities). CPS may enable theimplementation and exploitation of massive amounts of interconnected ICTdevices (sensors, actuators, processors microcontrollers, etc.) embeddedin physical objects at different locations. Mobile cyber physicalsystems, in which the physical system in question has inherent mobility,are a subcategory of cyber-physical systems. Examples of mobile physicalsystems include mobile robotics and electronics transported by humans oranimals.

Additionally, although the apparatuses have been depicted as singleentities, different units, processors and/or memory units (not all shownin FIG. 1) may be implemented.

5G enables using multiple input-multiple output (MIMO) antennas, manymore base stations or nodes than the LTE (a so-called small cellconcept), including macro sites operating in co-operation with smallerstations and employing a variety of radio technologies depending onservice needs, use cases and/or spectrum available. 5G mobilecommunications supports a wide range of use cases and relatedapplications including video streaming, augmented reality, differentways of data sharing and various forms of machine type applications(such as (massive) machine-type communications (mMTC), includingvehicular safety, different sensors and real-time control. 5G isexpected to have multiple radio interfaces, namely below 6 GHz, cmWaveand mmWave, and also being integrable with existing legacy radio accesstechnologies, such as the LTE. Integration with the LTE may beimplemented, at least in the early phase, as a system, where macrocoverage is provided by the LTE and 5G radio interface access comes fromsmall cells by aggregation to the LTE. In other words, 5G is planned tosupport both inter-RAT operability (such as LTE-5G) and inter-RIoperability (inter-radio interface operability, such as below 6GHz-cmWave, below 6 GHz-cmWave-mmWave). One of the concepts consideredto be used in 5G networks is network slicing in which multipleindependent and dedicated virtual sub-networks (network instances) maybe created within the same infrastructure to run services that havedifferent requirements on latency, reliability, throughput and mobility.

The current architecture in LTE networks is fully distributed in theradio and fully centralized in the core network. The low latencyapplications and services in 5G require to bring the content close tothe radio which leads to local break out and multi-access edge computing(MEC). 5G enables analytics and knowledge generation to occur at thesource of the data. This approach requires leveraging resources that maynot be continuously connected to a network such as laptops, smartphones,tablets and sensors. MEC provides a distributed computing environmentfor application and service hosting. It also has the ability to storeand process content in close proximity to cellular subscribers forfaster response time. Edge computing covers a wide range of technologiessuch as wireless sensor networks, mobile data acquisition, mobilesignature analysis, cooperative distributed peer-to-peer ad hocnetworking and processing also classifiable as local cloud/fog computingand grid/mesh computing, dew computing, mobile edge computing, cloudlet,distributed data storage and retrieval, autonomic self-healing networks,remote cloud services, augmented and virtual reality, data caching,Internet of Things (massive connectivity and/or latency critical),critical communications (autonomous vehicles, traffic safety, real-timeanalytics, time-critical control, healthcare applications).

The communication system is also able to communicate with othernetworks, such as a public switched telephone network or the Internet112, or utilize services provided by them. The communication network mayalso be able to support the usage of cloud services, for example atleast part of core network operations may be carried out as a cloudservice (this is depicted in FIG. 1 by “cloud” 114). The communicationsystem may also comprise a central control entity, or a like, providingfacilities for networks of different operators to cooperate for examplein spectrum sharing.

The technology of Edge cloud may be brought into a radio access network(RAN) by utilizing network function virtualization (NFV) and softwaredefined networking (SDN). Using the technology of edge cloud may meanaccess node operations to be carried out, at least partly, in a server,host or node operationally coupled to a remote radio head or basestation comprising radio parts. It is also possible that node operationswill be distributed among a plurality of servers, nodes or hosts.Application of cloudRAN architecture enables RAN real time functionsbeing carried out at the RAN side (in a distributed unit, DU 104) andnon-real time functions being carried out in a centralized manner (in acentralized unit, CU 108).

It should also be understood that the distribution of labour betweencore network operations and base station operations may differ from thatof the LTE or even be non-existent. Some other technology advancementsprobably to be used are Big Data and all-IP, which may change the waynetworks are being constructed and managed. 5G (or new radio, NR)networks are being designed to support multiple hierarchies, where MECservers can be placed between the core and the base station or nodeB(gNB). It should be appreciated that MEC can be applied in 4G networksas well.

5G may also utilize satellite communication to enhance or complement thecoverage of 5G service, for example by providing backhauling. Possibleuse cases are providing service continuity for machine-to-machine (M2M)or Internet of Things (IoT) devices or for passengers on board ofvehicles, or ensuring service availability for critical communications,and future railway/maritime/aeronautical communications. Satellitecommunication may utilise geostationary earth orbit (GEO) satellitesystems, but also low earth orbit (LEO) satellite systems, in particularmega-constellations (systems in which hundreds of (nano)satellites aredeployed). Each satellite 106 in the mega-constellation may coverseveral satellite-enabled network entities that create on-ground cells.The on-ground cells may be created through an on-ground relay node 104or by a gNB located on-ground or in a satellite.

It is obvious for a person skilled in the art that the depicted systemis only an example of a part of a radio access system and in practice,the system may comprise a plurality of (e/g)NodeBs, the device may havean access to a plurality of radio cells and the system may comprise alsoother apparatuses, such as physical layer relay nodes or other networkelements, etc. At least one of the (e/g)NodeBs or may be aHome(e/g)nodeB. Additionally, in a geographical area of a radiocommunication system a plurality of different kinds of radio cells aswell as a plurality of radio cells may be provided. Radio cells may bemacro cells (or umbrella cells) which are large cells, usually having adiameter of up to tens of kilometers, or smaller cells such as micro-,femto- or picocells. The (e/g)NodeBs of FIG. 1 may provide any kind ofthese cells. A cellular radio system may be implemented as a multilayernetwork including several kinds of cells. Typically, in multilayernetworks, one access node provides one kind of a cell or cells, and thusa plurality of (e/g)NodeBs are required to provide such a networkstructure.

For fulfilling the need for improving the deployment and performance ofcommunication systems, the concept of “plug-and-play” (e/g)NodeBs hasbeen introduced. Typically, a network which is able to use“plug-and-play” (e/g)Node Bs, includes, in addition to Home (e/g)NodeBs(H(e/g)nodeBs), a home node B gateway, or HNB-GW (not shown in FIG. 1).A HNB Gateway (HNB-GW), which is typically installed within anoperator's network may aggregate traffic from a large number of HNBsback to a core network.

Network slicing described briefly in Background allows a networkoperator to provide dedicated virtual networks over a common networkinfrastructure. The different virtual or logical networks may bedesigned to provide different networking characteristics such asdifferent qualities of service (QoS) including the QoS at signallinglevel (e.g. service resiliency, dimensioning, location of the networkfunctions). For example, the virtual networks may be customized to meetspecific needs of various applications, services, devices, customersand/or operators. Network slicing thus enables support for numerous andvaried services envisaged in 5G, for example.

In a system employing the network slicing, e.g. the system of FIG. 1, asingle physical network or a group of networks is sliced into multiplevirtual networks (slices) that can support different radio accessnetworks (RANs) or different service types running across a single RAN.The network slicing may be used to partition a core network of acellular communication system such as a 5G system, but it may also beimplemented in the RAN such as the WLAN or cellular RAN.

Each network slice may be optimized to provide resources and networktopology for the specific service and traffic that will use the slice.Network resources may be allocated according to requirements in terms ofmobility, capacity, connectivity and coverage such that particulardemands of each use case will be met. Physical network components orresources may be shared across different network slices.

Each network slice may be isolated from other network slices so that nonetwork slice interferes with the traffic in another network slice. Eachnetwork slice may be configured with its own network architecture,engineering mechanism and network provisioning. The network slicetypically contains management capabilities, which may be controlled bythe network operator or the customer, depending on the use case. Thenetwork slice may be independently managed and orchestrated. The userexperience of the network slice will be the same as if it was aphysically separate network.

For example, an autonomous car will rely on V2X (vehicle-to-anything)communication which requires low latency but not necessarily a highthroughput. The URLLC network slice described in Background may providea suitable networking service. A streaming service consumed while thecar is in motion will require a high throughput and is susceptible tolatency. The eMBB network slice described in Background may provide asuitable networking service for such an application. Both networkingservices can be delivered over the same common physical network(s) ondifferent virtual network slices.

Each virtual network (network slice) comprises a unique identifier. 3GPPspecifications define Single Network Slice Selection AssistanceInformation (S-NSSAI) and Network Slice Selection Assistance Information(NSSAI i.e. a collection of S-NSSAI) for such a purpose. A device mayreadily have NSSAI values and application mappings that linkapplications to the network slices. The NSSAI values may be provided bya cellular communication system, or the NSSAI values may exist in asubscriber identification module (SIM) or equivalent identity card ofthe device 100. Slice identification may also take other form than 3GPPNSSAI.

FIG. 2A illustrates an embodiment of the network slicing. The accessnode 104 may provide access to one or more sliced networks illustratedby the network slices 120, 130. The network slice 120 may be establishedto an end device 126 that may be a network element of a PLMN, a networkelement of a private network, or a server or a similar device in apublic network such as the Internet. The end device may be a networkelement of a core network of a cellular communication system such as a5G system, or a network residing on top of the core network. In asimilar manner, the network slice 130 may be established to an enddevice 136 that may be a network element of the PLMN or a privatenetwork. The end devices 126, 136 may be different network elements, andthey may belong to the same network or different networks. The slicesmay employ at least partially the same physical network components andhave unique slice identifiers, e.g. unique NSSAIs. Each network slice120, 130 may comprise control functions 122, 132 that control thefunctions of the network slices. Examples of the control functions mayinclude a session management function (SMF), a policy control function(PCF), and a network function repository function (NRF). SMF managesdata sessions, PCF manages roaming and mobility and routing policieswithin the network slice, and NRF maintains a network function profileof the network slice and supports the discovery of the network slice.Each network slice may also comprise user plane function(s) 124, 134that handle data transfer through the respective network slice.Additionally, there may be network functions 140 that are common tomultiple network slices 120, 130. Such common functions 140 may include,for example, a network slice detection function (NSSF) and/or an accessand mobility management function (AMF). Network slice instance selectionfor the terminal device 100 may be triggered as a part of a registrationprocedure by the AMF that receives the registration request from theterminal device 100. The AMF retrieves the slices that are allowed byuser subscription and interacts with the selection of the networkslice(s) for the terminal device 100, e.g. as in the embodimentsdescribed below.

3GPP specifications describe network slice instance lifecycle managementas depicted in FIG. 2B. A network slice is first designed in apreparation phase 200. Then, it is instantiated in step 202, comprisingan instantiation phase, a configuration phase, and an activation phase.Then, the network slice is operational in step 204 where the networkslice may be monitored and, if deemed necessary, modified. Finally, thenetwork slice may be decommissioned (step 206) when the network slice isno longer needed. Accordingly, the network slices may be dynamicallygenerated, modified, and terminated, as deemed beneficial for thesystem.

Conventionally, the network slice selection policies for the terminaldevice are determined in a network node of the network infrastructure,e.g. by the PCF in the core network. Current policies rely on the PCFsending rules (e.g. an UE route selection policy (URSP) as defined in3GPP specifications) to the UE where the rules map an applicationidentifier or a target destination, e.g. an internet protocol (IP)address range, for application traffic towards a slice that is to beselected by the UE for the corresponding traffic. However, there arenumerous different applications running in the various terminal devices,and provision of such information in the network infrastructure may becomplicated. This is complicated because it requires the operator to beaware of all applications that get proposed in the application store andbe aware of the requirements of such applications. Most applications caneasily use a baseline (default) slice for eMBB but some may havespecific requirements that the operator is not aware of. This is why ithas been recognized by the authors of this paper that the network slicemay need to be selected on the basis of requirements provided by the UE,e.g. in terms of quality-of-service (QoS) requirements. The QoSrequirements are specified by a type of data that is supposed to bedelivered, and the type of data is associated with an application thatneeds the data delivery. For example, a data streaming application (e.g.video application) will set different QoS requirements than an e-mailapplication, and an IoT sensor may set different QoS requirements than aV2X application. The QoS requirements may be accurate or less accuratein view of the true operation of the application and, therefore, it maybe beneficial to have more detailed information on the applicationavailable.

FIGS. 3 and 4 illustrate processes for performing the network sliceselection according to some embodiments. Referring to FIG. 3, a processexecuted in the terminal device comprises: triggering (block 300)network slice selection in the terminal device for an applicationexecuted in the terminal device; in response to said triggering,transmitting (block 302) a network slice query request message to anetwork node of a network infrastructure; receiving (block 304), fromthe network node as a response to the network slice query requestmessage, a network slice query response message indicating at least onenetwork slice available to the terminal device and comprising at leastone quality-of-service parameter of the at least one network slice;selecting (block 306) a network slice of the at least one network slicefor the application on the basis of the at least one quality-of-serviceparameter.

Referring to FIG. 4, the process executed in the network comprises:receiving (block 400) the network slice query request message from theterminal device requesting for information on available network slices;determining (block 402) at least one network slice available to theterminal device; transmitting (block 402), to the terminal device as aresponse to the network slice query request message, the network slicequery response message indicating the at least one network sliceavailable to the terminal device and comprising at least onequality-of-service parameter of the at least one network slice;receiving (block 406), from the terminal device, a message indicatingselection of a network slice for an application executed in the terminaldevice; and configuring (block 406) a routing policy data of theapplication in the selected network slice in the cellular networkinfrastructure.

Block 406 may include establishment of the routing policy or update ofan existing routing policy for the terminal device or for theapplication.

Implementing the network slice selection for an application in theterminal device improves the slice selection by better adaptationbetween the slice capabilities and the characteristics of theapplication. The terminal device may take into account information thatis not conventionally available to the PCF, such as detailedcharacteristics of the data transfer for the application. For example,the QoS requirements sent to the PCF define the requirements on ageneral level in terms of reliability, throughput, latency etc. Datatraffic pattern of applications may be highly variable between variousapplications and operators may not be aware of all applications and suchinformation cannot be taken into account in the conventional solutions.

FIG. 5 illustrates a signalling diagram of an embodiment that combinesthe processes of FIGS. 3 and 4. Referring to FIG. 5, the procedure maystart with block 300 that may be triggered upon launching or installingthe application in the terminal device, upon reception of a new datatransfer service request from a running application, or upon theterminal device entering a new service area through mobility. Therequest from the application may define determined quality-of-serviceconstraints required by the application. The application may specify QoSrequirements for the data transfer service. A slice selection manager inthe terminal device may the evaluate the QoS requirements in view of thecurrent data routing policy or policies established for one or moreother applications in the terminal device. If the slice selectionmanager finds that one or more currently used network slices meets theQoS requirements, the terminal device may select one of the networkslices and the procedure of FIG. 5 may move directly to existing 3GPPR16 mechanisms. If a suitable network slice cannot be found amongst thecurrently used network slices, the procedure may proceed to steps 302and 400 where the terminal device requests the network node to providethe information on the network slices currently available to theterminal device.

In an embodiment, the network slice query request transferred in steps302 and 400 comprises at least one information element indicating anidentity of the application.

In an embodiment, the network slice query request comprises at least oneinformation element specifying at least one criterion, e.g. a QoSrequirement. The QoS requirement may comprise at least one of thefollowing required of the network slice for the application: minimumthroughput, minimum latency, minimum reliability, and charginginformation.

In an embodiment, the network node is the PCF and step 302 and 304 maybe carried via non-access stratum (NAS), e.g. via the AMF.

In an embodiment, the network node is a network slice selection supportfunction comprised in the PCF or in another element of the network, e.g.the core network.

A network slice repository 500 may store information on currently activenetwork slices and information on access permissions. The repository maybe stored in an unified data repository (UDR) of the 5G network, forexample. In step 402, the network node may access the slice repository500 to acquire information on those one or more network slices that meetthe at least one criterion specified in the network slice query requestand/or to which the terminal device has access permissions (usersubscription data). If no such network slice is currently operational,block 502 may be executed where the network node issues a network slicepreparation and instantiation request to a slice manager, e.g. amanagement and orchestration function (MANO). Accordingly, blocks 200and 202 may be executed in block 502.

Upon acquiring information on the one or more network slices suitablefor the terminal device, the network node adds the information on thenetwork slice(s) to the network slice query response, and the responseis delivered to the terminal device in steps 304 and 404. The responsemay include identifiers of each network slice comprised in the response.Each identifier of a network slice may be a single network sliceselection assistance information (S-NSSAI). The response may compriseQoS parameters of the available network slices, e.g. any one of theparameters corresponding to the at least one criterion provided in thenetwork slice query request: throughput, latency, reliability, andcharging information. The parameters may be provided in terms ofguaranteed performance of each network slice. In other words, theresponse may indicate for each available network slice a guaranteedthroughput, guaranteed (maximum) latency, guaranteed (minimum)reliability, etc.

In block 504, the terminal device then selects one of the network slicesindicated in the response received in step 304. In the selection, theterminal device may use the parameters of the network slices provided inthe response and, additionally, requirements defined by the application.Table 1 illustrates an example of requirements that may be defined bythe application:

TABLE 1 Application Network Slice Identifier Traffic identifierRequirement Remark App #1 Augmented/Virtual Throughput: >20 MinimumReality Traffic Mbps requirements Latency: <50 ms Throughput: >50Preferred Mbps requirements Latency: <20 ms Reliability: MediumThroughput: 100 High Quality Mbps Latency: <10 ms Reliability: HighPayment Traffic Reliability: High Minimum Latency: <1000 ms requirementsThroughput: >1 Mbps Reliability: Very Preferred High requirementsLatency: <1000 ms Throughput: >1 Mbps

As described above, an advantage of the invention is that moreinformation on the requirements or preferences of the applications maybe taken into account. QoS requirements typically specify only minimumrequirements for the data transfer and, therefore, the selectionperformed in the network may not reach the full potential in theselection.

Table 1 shows one example of an application requirement profile. Thisprofile may be provided by the application to define its specificrequirements of the network slice. At least one network slicerequirement may be provided in the profile. To improve the selection,multiple network slice requirements may be provided, for differentservice levels, e.g. the minimum service level, preferred service level,high quality level as in Table 1. Since there may be different traffictypes used by an application, the group of network slice requirementscan also be set base on specific traffic type instead of applicationtype, as illustrated in Table 1.

Block 504 may comprise searching the available network slices to find anetwork slice that can provide a service level as high as possible. Forexample, block 504 may first comprise checking for a network slice thatprovides the highest requirements. If such is found, then that networkslice is selected, e.g. to meet the high-quality requirements of theapplication. Then, the application will get the best benefit of the datatransfer. If such a network slice cannot be found, then the lower(preferred) requirements are cross-referenced with the parameters of theavailable network slices. Accordingly, the most suitable network sliceavailable for the application will be selected in block 504.

If there are other criteria for the network slice selection on terminaldevice, such as the highest acceptable charging rate, block 504 may takesuch criteria into account as well. Based on the applicationrequirements, block 504 may select a network slice that can provide aservice level as high as possible with the condition of meeting alllocal provisioning thresholds such as the maximum charging rate. This isfurther refined in connection with FIG. 6.

Upon selecting the network slice for the application, the terminaldevice may transmit to the network node a request to configure a routingpolicy for data of the application in the selected network slice (step506). The request may comprise at least one information elementindicating an identity of the application and, in some embodiments,selected network slice information. Upon receiving the request, thenetwork node may establish/update a routing policy for the applicationin the selected network slice (block 508). The routing policy may beestablished in accordance with UE route selection policy (URSP) asdefined in 3^(rd) Generation Partnership Project (3GPP) specificationsfor 5G. Upon establishing/updating the routing policy for theapplication in the selected network slice, the network node may respondto the terminal device in step 510 and indicate completion of therouting policy. Step 510 may follow the PCF downloading the routingpolicy to the terminal device, e.g. via an USRP provisioning interfaceof the 3GPP specifications for 5G. Once the routing policy is receivedby the terminal device in step 510, the terminal device may verify therouting policy and start transfer of application data over the networkslice according to the routing policy (block 512).

In an embodiment, the terminal device indicates in step 506 informationon the application, e.g. the above-described QoS parameters of theapplication. The network node may use this information whenestablishing/updating the routing policy.

FIG. 6 illustrates an embodiment of the slice selection process (block306 or 504) in the terminal device. Referring to FIG. 6, the process maystart in block 600 where one of the network slices available to theterminal device is selected. In block 602, the QoS parameters of thepicked network slice are retrieved as well as the applicationrequirements, e.g. the requirements set out in Table 1. In block 604,the QoS parameters are compared with the application requirements. Ifthe QoS parameters of the network slice meet the applicationrequirements, the process proceeds to block 606. Otherwise, the processterminates for the picked network slice and proceeds to block 612.

In block 606, it is determined whether or not the slice is the firstslice that meets the application requirements. If yes, the slice isstored as a preferred slice in block 608. Otherwise, the slices thatmeet the application requirements are compared in block 610 and one thatcan better meet the application requirements is selected as thepreferred slice in block 610. For example, if a first slice is capableof meeting the minimum requirements of the application while a secondslice is capable of meeting the preferred requirements of theapplication, the second slice is preferred over the first slice becauseof the capability of meeting the higher preferences of the application.From blocks 608 and 610, the process may proceed to block 612. In block612, it is determined whether there are one or more slices that have notyet been considered. If yes, the process proceeds to block 600 whereanother slice that has not yet been picked will be picked. If all theavailable network slices have been considered, the process proceeds toblock 614.

In block 614, it is determined whether or not the preferred slice hasbeen stored, i.e. whether or not block 608 has been executed. If yes,the current preferred slice is selected in block 616. If no preferredslice meeting the application requirements has not been discoveredamongst the network slices currently available to the terminal device,the process proceeds to block 618.

In block 618, it is resolved whether or not a slice can be provided tothe application. If a slice reported by the network to the UE as acandidate for selection has been associated by the network with anindication that this slice has not (yet) been subscribed by the user,block 618 may comprise outputting a notification to a user of theterminal device via a user interface. The notification may inform theuser of the situation of not finding a network slice (or connection)that would meet all the specifications and request the user to confirmwhether or not the slice not currently subscribed to may be selected.Based on the user positive input, the process proceeds to the web pageprovided by the network in step 304/404 and, if the followingsubscription succeeds on the web page, proceeds to select thecorresponding network slice. Otherwise, if the user input indicatesdecline to subscribe to the new slice, or the subscription processfails, etc. . . . , the terminal device may consider this slice is notsuitable for selection.

In an embodiment, the network node may in block 402 determine alsonetwork slices to which the terminal device currently has no permissionsand provide such network slices in the response (step 404) as well. Suchnetwork slices may be associated with an information element serving asan indicator of the lacking access permissions. In such an embodiment,block 306 or 618 may comprise proposing such a network slice to the uservia the user interface in a situation where no network slice meeting theapplication requirements can be found amongst the network slices towhich there are valid access permissions. The user may then selectwhether or not (s)he wishes to update the access permissions. If theuser approves the update, the user may be directed to a procedure wherethe access permissions are controlled, e.g. via a uniform resourcelocator (URL). The URL may be provided by the network node in step 404in a case where the response includes at least one network slice towhich the terminal device has no access permissions currently. When theuser has updated the access permissions by managing his/hersubscription, a new set of one or more network slices becomes availableto the terminal device, and a network slice meeting the applicationrequirements may be accessible to the terminal device and selected forthe application.

FIG. 7 illustrates an embodiment of a structure of the above-mentionedfunctionalities of an apparatus executing the functions of the networknode in the process of FIG. 4 or any one of its embodiments. Theapparatus may be a network node for the core network of a cellularcommunication system, e.g. for a PCF. In another embodiment, theapparatus carrying out the above-described functionalities of thenetwork node is comprised in such an entity, e.g. the apparatus maycomprise a circuitry, e.g. a chip, a chipset, a processor, a microcontroller, or a combination of such circuitries in the PCF. Theapparatus may be an electronic device comprising electronic circuitriesfor realizing some embodiments of the network node.

Referring to FIG. 7, the apparatus may comprise a communicationinterface 22 or a communication circuitry configured to provide theapparatus with capability for bidirectional communication with othernetwork nodes such as the access node 104 and the AMF, and also with theterminal device. The communication interface 22 may comprise circuitriesfor processing messages received from the terminal device and messagestransmitted to the terminal device in the above-described embodiments.The communication interface 22 may comprise standard well-knowncomponents such as a modem, an amplifier, a filter, a frequencyconverter, and encoder/decoder circuitries.

The apparatus may further comprise a memory 20 storing one or morecomputer program products 24 configuring the operation of at least oneprocessor 10 of the apparatus. The memory 20 may further store aconfiguration database storing operational configurations of theapparatus, e.g. the rule of whether or not including the information onthe network slices to which the terminal device has no accesspermissions in the network slice query response.

The apparatus may further comprise the at least one processor 10configured to carry out the process of FIG. 4 or any one of itsembodiments. Referring to FIG. 8, the processor(s) 10 may comprise amodule 14 executing at least some of the above-described functions ofthe PCF. The module 14 may comprise the above-described NSSSF module 12configured to execute the steps of FIG. 4. When executing block 402, theNSSSF may employ a slice information acquisition module 16 configured toretrieve the required information on the network slices from the slicerepository 500, if the repository is not stored locally at the memory20.

FIG. 8 illustrates an embodiment of a structure of the above-mentionedfunctionalities of the apparatus 100 executing the process of FIG. 3 orany one of the embodiments performed by the terminal device 100. Theapparatus may be the terminal device or, in some embodiments, theapparatus may be a circuitry or an electronic device realizing someembodiments of the invention in the terminal device. The apparatus maycomply with 3GPP specifications for 5G and/or IEEE 802.11 technologythat connects the terminal device to the core network of the cellularcommunication system via an 802.11 radio interface. The apparatus may beor may be comprised in a computer (PC), a laptop, a tablet computer, acellular phone, a palm computer, a sensor device, or any other apparatusprovided with radio communication capability. In another embodiment, theapparatus carrying out the above-described functionalities is comprisedin such a device, e.g. the apparatus may comprise a circuitry such as achip, a chipset, a processor, a micro controller, or a combination ofsuch circuitries in any one of the above-described devices. Theapparatus may be an electronic device comprising electronic circuitriesfor realizing some embodiments of the present invention.

Referring to FIG. 8, the apparatus may comprise a radio interfaceproviding the apparatus with radio communication capability within awireless network. The radio interface 70 may comprise a radio modemsupporting the 5G specifications and/or IEEE 802.11 technology. Theradio interface 70 may further comprise a radio frequency (RF) front endcomprising standard well-known components such as an amplifier, filter,frequency-converter, (de)modulator, and encoder/decoder circuitries andone or more antennas.

The apparatus may further comprise a memory 60 storing one or morecomputer program products 62 configuring the operation of at least oneprocessor of the apparatus. The memory 60 may further store aconfiguration database 64 storing operational configurations of theapparatus. The configuration database 64 may, for example, store thenetwork slices and corresponding slice identifiers the apparatus isconfigured to support, routing policies for applications currentlytransferring data, etc. The configuration database may further store theapplication requirements of applications executed in the apparatus.

The apparatus may further comprise the at least one processor 50managing the operation of the apparatus. The at least one processor 50may comprise an application processor 56 forming an application layer.The application processor may execute computer programs forming theprimary function of the apparatus. For example, if the apparatus is asensor device, the application processor may execute one or more signalprocessing applications processing measurement data acquired from one ormore sensor heads. If the apparatus is a computer system of a vehicle,the application processor may execute a media application and/or anautonomous driving and navigation application. The application processor56 may generate data to be transmitted over the radio interface andreceive data through the radio interface. The application processor mayoutput data transfer requests to a connection manager comprising a sliceselection manager 54. The slice selection manager 54 may performselection of network slices to applications needing data transferservices. The slice selection manager may implement the process of FIG.3. The apparatus may further comprise a routing manager configured toreceive the routing policy in step 510 and to implement data transferfor the application over the selected network slice by using thereceived routing policy. The routing policy may define, for example, aprotocol data unit (PDU) session to be used for the application data,associated traffic and service descriptors, etc.

This definition of ‘circuitry’ applies to uses of this term in thisapplication. As a further example, as used in this application, the term“circuitry” would also cover an implementation of merely a processor (ormultiple processors) or portion of a processor, e.g. one core of amulti-core processor, and its (or their) accompanying software and/orfirmware. The term “circuitry” would also cover, for example and ifapplicable to the particular element, a baseband integrated circuit, anapplication-specific integrated circuit (ASIC), and/or afield-programmable grid array (FPGA) circuit for the apparatus accordingto an embodiment of the invention. The processes or methods described inFIGS. 3 to 6 may also be carried out in the form of one or more computerprocesses defined by one or more computer programs. A separate computerprogram may be provided in one or more apparatuses that executefunctions of the processes described in connection with the Figures. Thecomputer program(s) may be in source code form, object code form, or insome intermediate form, and it may be stored in some sort of carrier,which may be any entity or device capable of carrying the program. Suchcarriers include transitory and/or non-transitory computer media, e.g. arecord medium, computer memory, read-only memory, electrical carriersignal, telecommunications signal, and software distribution package.Depending on the processing power needed, the computer program may beexecuted in a single electronic digital processing unit or it may bedistributed amongst a number of processing units.

Embodiments described herein are applicable to wireless networks definedabove but also to other access networks including e.g. wireline, orother kinds of wireless networks. The protocols used, the specificationsof the wireless networks and their network elements develop rapidly.Such development may require extra changes to the described embodiments.Therefore, all words and expressions should be interpreted broadly andthey are intended to illustrate, not to restrict, the embodiment. Itwill be obvious to a person skilled in the art that, as technologyadvances, the inventive concept can be implemented in various ways.Embodiments are not limited to the examples described above but may varywithin the scope of the claims.

1. An apparatus for a terminal device, said apparatus comprising: atleast one processor; and at least one memory including computer programcode, the at least one memory and computer program code configured to,with the at least one processor, cause the apparatus to: trigger networkslice selection in the terminal device for an application executed inthe terminal device; in response to said triggering, cause transmissionof a network slice query request message to a network node of a networkinfrastructure, wherein the network slice query request messagecomprises at least one information element specifying at least onecriterion comprising at least one of a quality-of-service requirementand charging information; receive, from the network node as a responseto the network slice query request message, a network slice queryresponse message indicating at least one network slice available to theterminal device and comprising at least one quality-of-service parameterof the at least one network slice, wherein the at least one networkslice indicated by the network slice query response message meets the atleast one criterion of the network slice query request message; andselect a network slice of the at least one network slice for theapplication on the basis of the at least one quality-of-serviceparameter.
 2. The apparatus of claim 1, wherein the at least one memoryand computer program code configured to, with the at least oneprocessor, cause the apparatus to perform said selecting by at leasttransmitting to the network node a request to configure a routing policyfor data of the application in the selected network slice.
 3. Theapparatus of claim 2, wherein the request to configure the routingpolicy comprises at least one information element indicating an identityof the application.
 4. The apparatus of claim 1, wherein the at leastone memory and computer program code configured to, with the at leastone processor, cause the apparatus to perform said triggering asresponsive to the application requesting for data transfer withdetermined quality-of-service constraints.
 5. An apparatus for a networknode of a network infrastructure, said apparatus comprising: at leastone processor; and at least one memory including computer program code,wherein the at least one memory and computer program code configured to,with the at least one processor, cause the apparatus to: receive anetwork slice query request message from a terminal device requestingfor information on available network slices, wherein the network slicequery request message comprises at least one information elementspecifying at least one criterion comprising at least one of aquality-of-service requirement and charging information; determine atleast one network slice available to the terminal device and meeting theat least one criterion of the network slice query request message;transmit, to the terminal device as a response to the network slicequery request message, a network slice query response message thatindicates the at least one network slice available to the terminaldevice, meeting the at least one criterion of the network slice queryrequest message, and that comprises at least one quality-of-serviceparameter of the at least one network slice; receive, from the terminaldevice, a message indicating a selection of a network slice for anapplication executed in the terminal device; and configure a routingpolicy for data of the application in the selected network slice in thenetwork infrastructure.
 6. The apparatus of claim 5, wherein the messageindicating the selection of the network slice comprises at least oneinformation element indicating an identity of the application.
 7. Theapparatus of claim 5, wherein the network slice query request messagecomprises at least one information element specifying at least onecriterion, and wherein the at least one memory and computer program codeconfigured to, with the at least one processor, cause the apparatus toinclude in the network slice query response message network slices thatmeet the at least one criterion and exclude from the network slice queryresponse message at least one network slice not meeting the at least onecriterion.
 8. A method for a terminal device, said method comprising:triggering, by the terminal device, network slice selection in theterminal device for an application executed in the terminal device;transmitting, by the terminal device in response to said triggering, anetwork slice query request message to a network node of a networkinfrastructure, wherein the network slice query request messagecomprises at least one information element specifying at least onecriterion comprising at least one of a quality-of-service requirementand charging information; receiving, by the terminal device from thenetwork node as a response to the network slice query request message, anetwork slice query response message indicating at least one networkslice available to the terminal device and comprising at least onequality-of-service parameter of the at least one network slice, whereinthe at least one network slice indicated by the network slice queryresponse message meets the at least one criterion of the network slicequery request message; and selecting, by the terminal device, a networkslice of the at least one network slice for the application on the basisof the at least one quality-of-service parameter.
 9. The method of claim8, wherein said selecting comprises transmitting to the network node arequest to configure a routing policy for data of the application in theselected network slice.
 10. The method of claim 9, wherein the requestto configure the routing policy comprises at least one informationelement indicating an identity of the application.
 11. A method for anetwork node of a network infrastructure, said method comprising:receiving, by the network node, a network slice query request messagefrom a terminal device requesting for information on available networkslices, wherein the network slice query request message comprises atleast one information element specifying at least one criterioncomprising at least one of a quality-of-service requirement and charginginformation; determining, by the network node, at least one networkslice available to the terminal device and meeting the at least onecriterion of the network slice query request message; transmitting, bythe network node to the terminal device as a response to the networkslice query request message, a network slice query response message thatindicates the at least one network slice available to the terminaldevice, meeting the at least one criterion of the network slice queryrequest message, and that comprises at least one quality-of-serviceparameter of the at least one network slice; receiving, by the networknode from the terminal device, a message indicating selection of anetwork slice for an application executed in the terminal device; andconfiguring, by the network node, a routing policy for data of theapplication in the selected network slice in the network infrastructure.12. The method of claim 11, wherein the message indicating the selectionof the network slice comprises at least one information elementindicating an identity of the application.
 13. The method of claim 11,further comprising excluding, by the network node, from the networkslice query response message at least one network slice not meeting theat least one criterion.
 14. A computer program product embodied on anon-transitory computer-readable medium, and comprising a computerprogram code readable by a computer, wherein the computer program codeconfigures the computer to carry out a computer process for a terminaldevice, comprising: triggering network slice selection in the terminaldevice for an application executed in the terminal device; transmitting,in response to said triggering, a network slice query request message toa network node of a network infrastructure, wherein the network slicequery request message comprises at least one information elementspecifying at least one criterion comprising at least one of aquality-of-service requirement and charging information; receiving, fromthe network node as a response to the network slice query requestmessage, a network slice query response message indicating at least onenetwork slice available to the terminal device and comprising at leastone quality-of-service parameter of the at least one network slice,wherein the at least one network slice indicated by the network slicequery response message meets the at least one criterion of the networkslice query request message; and selecting a network slice of the atleast one network slice for the application on the basis of the at leastone quality-of-service parameter.
 15. A computer program productembodied on a non-transitory computer-readable medium, and comprising acomputer program code readable by a computer, wherein the computerprogram code configures the computer to carry out a computer process fora network node of a network infrastructure, comprising: receiving anetwork slice query request message from a terminal device requestingfor information on available network slices, wherein the network slicequery request message comprises at least one information elementspecifying at least one criterion comprising at least one of aquality-of-service requirement and charging information; determining atleast one network slice available to the terminal device and meeting theat least one criterion of the network slice query request message;transmitting, to the terminal device as a response to the network slicequery request message, a network slice query response message thatindicates the at least one network slice available to the terminaldevice, meeting the at least one criterion of the network slice queryrequest message, and that comprises at least one quality-of-serviceparameter of the at least one network slice; receiving, from theterminal device, a message indicating selection of a network slice foran application executed in the terminal device; and configuring, by thenetwork node, a routing policy for data of the application in theselected network slice in the network infrastructure.
 16. A computerprogram product embodied on a non-transitory computer-readable medium,and comprising a computer program code readable by a computer, whereinthe computer program code configures the computer to carry out acomputer process comprising the method according to claim
 9. 17. Asystem comprising: a first apparatus for a terminal device, comprisingat least one processor and at least one memory including computerprogram code, the at least one memory and computer program codeconfigured to, with the at least one processor, cause the firstapparatus to: trigger network slice selection in the terminal device foran application executed in the terminal device; in response to saidtriggering, cause transmission of a network slice query request messageto a network node of a network infrastructure, wherein the network slicequery request message comprises at least one information elementspecifying at least one criterion comprising at least one of aquality-of-service requirement and charging information; receive, fromthe network node as a response to the network slice query requestmessage, a network slice query response message indicating at least onenetwork slice available to the terminal device and comprising at leastone quality-of-service parameter of the at least one network slice,wherein the at least one network slice indicated by the network slicequery response message meets the at least one criterion of the networkslice query request message; and select a network slice of the at leastone network slice for the application on the basis of the at least onequality-of-service parameter; and a second apparatus for the networknode, comprising at least one processor and at least one memoryincluding computer program code, wherein the at least one memory andcomputer program code configured to, with the at least one processor,cause the second apparatus to: receive the network slice query requestmessage from the terminal device requesting for information on availablenetwork slices, wherein the network slice query request messagecomprises at least one information element specifying at least onecriterion comprising at least one of a quality-of-service requirementand charging information; determine at least one network slice availableto the terminal device and meeting the at least one criterion of thenetwork slice query request message; transmit, to the terminal device asa response to the network slice query request message, the network slicequery response message that indicates the at least one network sliceavailable to the terminal device, meeting the at least one criterion ofthe network slice query request message, and that comprises at least onequality-of-service parameter of the at least one network slice; receive,from the terminal device, a message indicating a selection of thenetwork slice for the application executed in the terminal device; andconfigure a routing policy for data of the application in the selectednetwork slice in the network infrastructure.